Treatment of aromatic hydrocarbons



kylated aromatic hydrocarbons.

Patented Dec. 12, 1944 TREATMENTYOF AROMATIC I nrnnooannons I Innis Schmerling and Arthur M. Durinski, Chi

onto, 11]., assilnors to Compa y, Chicago, 11! were No Drawing. Application Serial No..394,166

Universal Oil Product; I a corporation of Dela- 17 Claims. (Cl. 260-671) This invention relates to the treatment of arcmatic hydrocarbons to produce therefrom al- More specifically-the process i concerned with the interaction of an aromatic hydrocarbon and an alkyl or 5 aralkyl halide to produce mono-alkylated and poly-alkylated aromatic hydrocarbons.

It isrecognized thatbenzene has been cone verted into alkylated benzenes by treatment with an alkyl chloride in the presence or aluminum chloride. This reaction has the disadvantage that complex addition compounds are formed apparently involving the aluminum chloride and thus producing sludge-like materials which decrease the life of the aluminum chloride and interfere with continuousyoperation of the process. The present invention differentiates from the prior art on this subject in that the aromatic hydrocarbon and alkyl halide, this term being herein used broadlyto include both alkyl and aralkyl 2o halides, are caused to interact in the presence of :mrgaestor packing material as hereinafter, de-

In one specific embodiment the present invention comprises a processfor producing alkylated' aromatic hydrocarbons which includes contacting an aromatic hydrocarbon with an alkyl halide in the presence of a metal oxide catalyst under alkylating conditions of temperature and pressure Aromatic hydrocarbons, such as benzene, toluene, other alkylated benzenes, naphthalene, alkylated naphthalenes, other polynuclear aromatics, etc., which are alkylated by alkyl halides as hereinafter set forth, may be obtained by the distillation of coal, by the dehydrogenation andcyclization of aliphatic hydrocarbons and of a1-, kylated aromatic hydrocarbons; and bycoth'er means.

Alkylating agents suitable for use according to. 40

the process ofthe present invention comprise alkyl halides including particularly chlorides, bromides, and fluorides. Typical alkyl chlorides comprise the methyLethyl, propyl, and isopropyl ompounds as well as various butyl, pentyl, and

higher 81ml derivatives. Aralkyl halides, of

which benzyl chloride is typical, are, also utilizgble as alkylating agents for aromatic hydrocarons.

While the alkylation reaction occurs readily 5 in the absence of added catalytic material, the velocity of this reaction is increased by the presence within the reactor of one or more of a number of metal oxides or metal oxide-containing catalysts of which the following are representative: Zinc oxide, ferric oxide, magnesium oxide, aluminum oxide, bauxite, silica gel, diatomaceous earth, clays; composites of silica-alumina, silicaalumina-zirconia, silica-alumina-thoria, etc. These difi'erent catalytic'reactor packing materials may also be composited in many ways. Thus zinc oxide may be used as such or it may be supported on suitable carriers includingdiatomaceous earth, clays, various forms of alumina, silice-alumina composites, etc. The zinc oxide by a series of steps may be placed on the carrier which comprise impregnation of the carrier with an aqueous solutionof zinc nitrate, calcination of the nitrate to the oxide or by treating the supported zinc nitrate with a water-soluble carbonate to precipitate zinc carbonate which is then calcined to the oxide. Also, zinc oxide and another material such as alumina may be mixed intimately as powders and then pelleted to form packing material suitableforuse in the process.

.Alkylation of aromatic hydrocarbons of the I types hereinabove set forth are also carried out in the presence of hydrogen or of a hydrogencontaining gas. There'is relatively little forma-- tion of carbon and heavy hydrocarbonaceous material upon the reactor packing material when.

these conversion reactions are carriedout under hydrogen pressure, but carbon formation does occur to a substantial extent in the absence of added hydrogen.

In effecting reaction between benzene or another aromatic hydrocarbon and an alkyl halide according to the process of the present invention, the exact method of procedure varies with the nature of the reacting constituents as well as with the composition of the reactor packing material, the presence of which accelerates the alkylation reaction. A simple procedure which is used in alkylating benzene consists in contacting a mixture of benzene and an alkyl chloride, such as isopropyl chloride, with silica gel or another suitable reactor packing material at a temperature of from about 100 to about 500 C. and preferably from about 200to about 400 C. under a pressure of from substantially atmospheric to approximately 200 atmospheres or more. Intimate contact of the reacting components is efieoted by passing the reaction mixture over a fixed bed of the metal oxide reactor packing material or the reacting components may be mixed in the presence of finely powdered silica or other materials The reaction mixture undergoing treatment preferably contains between about 1 and'about 20 molecular proportions of aromatic hydrocarbon per 1 molecular proportion of alkyl treated, is introduced hydrocarbon and an alkyl chloride diminish production of polyreactor-containing a granular material such as a composite of zinc oxide and alumina, or at least a portion of the benzene is luted by another portion'of the benzene being the inlet and the outlet of the reaction zone in such a way that the mixture undergoing reaction will at all times contain a relatively low proportion of alkyl chloride and thus favor the production of mono-alkylated benzene rather than the formation of more-highly alkylated benzenes.

Hydrogen chloride formed during the alkylation of an aromatic hydrocarbon by an alkyl halide is recovered asa valuable 'by-product which may be utilized for any other purpose as desired or a portion of said hydrogen chloride may be commingled with the reactants charged to the process.

While the method of passing an alkyl halide and benzene or another aromatic hydrocarbon, either together or counter-currently, through a suitable reactor under suitable conditions of temperature and pressure in the presence of added granular packing material is the generally preterred procedure, the interaction or an alkyl halide and an aromatic hydrocarbon may also be eflected in batch type operation utilizing a closed vessel in. which some of the reacting constituents are in liquid phase and are maintained in intimate contact by some means agitation. The choice of operating procedure is dependent upon such circumstances as the temperature and pressure found to be most effective for producing the desired reaction between a particular aromatic or other alkyl halide. Y

In general theproducts formed by interaction of an alkyl halide with a molal excess oi an aromatic hydrocarbon reacted aromatic hydrocarbon by suitable means as by distillation and the unreacted portion of the aromatic hydrocarbon originally charged is returned to the process and commingled with additional quantities of the mixture of alkyl halide and aromatic lmdrooarbon being charged to reaction. Thusthe alkylated aromatic hydrocarbons may be substantially freed from theexcess of the originally charged aromatic hydrocarbon and then be separated into desired fractions or individual compounds by distillation at ordinary or reduced pressure or by other suitable means.

The following examples are given to illustrate the character of results obtained by the use of the present process, although the data presented are not introduced. with the intention of unduly gating the generally broad scope or the inven- A of 80 parts by weight of benzene, 39 parts by weight or isopropyl chloride, and parts by weight! alumina in the tormof 3 x --3 mm. pellets was placed in'an autoclave, hydrogen was added to an initial pressure or 100 atmoepheres. and thereaction mixturev was then heated tor 4 hours at 300C. 'I'he resulting reaction product yielded tie-parts by weight oi mono-isopropyl benzene and 16 parts by weisht of. poly-18 910931 benlene.

charged to a reactor while the alkyl halide as such or preferably diat various points between are separated from the un-.

EXAIVIPLE III A mixture of 80 parts by weight of benzene. 39 parts by weight or isopropyl chloride, 3 parts by weight of zinc oxide, and '1- parts by weight 0! aluminawas placed in the autoclave used in Example I, and hydrogen was added to 100 atmospheres initial pressure. The autoclave so charged was then heated for 4 hours at 300 C. and a total of 91 parts by weight of liquid hydrocarbons. was recovered which contained 83 parts by weight of mono-isopropyl benzene, 6.4 parts by weight of di-isopropyl benzene, and 3.6 parts by weight 01 more-highly alkylated benzene.

EXAMPLE IV parts by weight oi benzene, oi isopropyl chloride, and 10 3-8 mesh silica gel was placed toclave, hydrogen was added thereto to or 100 atmospheres, and thereheated for 4' hours at the with the results A mixture 01 80 parts by weight parts by weight of in an au a total pressure sulting mixture was temperatures indicated and shown in the following table:

Team:

of benzene with isopropyl chloride in the presence of silica gel Alklllutian isopropyl benzenes,

Maximum parts by wt.

pressure, atmos.

Higher Temp.,

ss sssssss -Glass-linsd autoclaveautoclave liner of glass e uipped with glass stopper containing capillary designed to mlninaze contact oi reaction mixture with the steel walls oi the autoclave.

I No hydrogen added.

In the absence of added silica gel otherwise identical reaction mixtures treated at 150 C. yielded 4 parts by weight of mono-isopropyl ben- Zone and 2 parts by weight of higher boiling material, while at 250 0., like reaction mixtures of benzene and isopropyl chloride yielded 10 part by weight of mono-isopropyl benzen 8 parts by weight or di-isopropyl benzene, and 6 parts by weight of higher boilin The above results the condensation of benzene with isopropyl chloride at temperatures-as low as 150 and 200 C. Better yields were obtained when no capill stopper was used on the glass liner of the auto the steel walls of the autoclave. In run 7s allwlation occurred also at 200? .C. under a reia XAMPLEV EXAMPLEVI 80 parts by weight of benzene, 25 parts by weight of methyl chloride, and 10 parts by weight of a synthetically prepared silica-alumina-zirconia catalyst were placed in a rotating autoclave under an initial nitrogen pressure of 30 atmospheres and then heated for 4 hours'at 300 C. under a maximum pressure of 110 atmospheres. The catalystused was a synthetically prepared material formed by compositing 100 molecular added hydroproportions of hydrated silica, 2 molecular pro and molecular portions of hydrated alumina, proportions of hydrated zirconia, washing the composite until substantially free from alkali metal compounds, drying the resulting precipitated material and then grinding said material, mixing it with 4% by weight of able for forming chine. The formed pellets were then calcined in air to remove the flour and stearic acid.

At the end of the reaction the autoclave was cooled and 85 parts by weight of yellow liquid and 12 parts by weight of black catalyst pellets were removed therefrom. The liquid product was found to contain 6 parts by weight o1v toluene. and 4.5 parts by weight of xylenes and morehighly methylated benzene. ,The toluene was identified by preparation or 2;4- di-nitr0toluene with a melting point of 70 C.

EXAMPLEVII 80 parts by weight of benzene, 70 parts by weight of isobutyl bromide, and parts by weight of 3 x 3 mm.- alumina pellets were charged to a. steel autoclave which was then placed under 30 atmospheres initial nitrogen pressure, rotated, and heated for 4 hours at 250 C. The 106 parts by weight of liquid reaction. products contained consisting essentially of an alkyl halide, and a" flour and 2% by weight of stearic acid to Iorma composite suitinto pellets. by a pelleting mamono-butyl from the specifiv rnolecular excess of an aromatic hydrocarbon to reaction -under alkylating conditions and in the Jresence of a solid alkylating catalyst consisting essentially of at least one metal oxide.

2. A process for producing alkylated aromatics portions of benzene which comprises subjecting anfalblating consisting essentially 01' an alkyl halide, anda molecular excess of an aromatic hydrocarbon to reaction at an alkylating temperature or from about C. to about 500? C. and in the presence of a solid alkylating catalyst consisting essentially of at least one metal oxide.

3. A process for producing an alkylated benzene which comprises contacting from about 1 to about 20 molecular proportions of benzene with 1 molecular proportion of an alkylating agent consisting essentially of an alkyl halide at a temperature of from about 100 to about 500- C. under a pressure of from substantially atmospheric to approximately 200 atmospheres in the presence of an alkylating catalyst consisting essentially of at least one metal oxide.

4.- A process for producing alkylated aromatic; which comprises subjecting a mono-halo-alkan'e and a molecular excess of an aromatic hydrocarbon to reaction under alkylating conditions and in the presence of a solid alkylating catalyst consisting essentially of at least one metal oxide comprising zinc oxide.

5. A process for producing alkylated aromatics which comprises subjecting a mono-halo-alkane C. to about 0. and in the presence of a solid alkylating catalyst co essentially of at least one metal oxide comprising zinc' oxide. X

6. A process for producing a substantial yield of mono-\alkylated benzene which comprises contacting from about 1 to about :0 molecular pro- I with 1 molecular proportion of an alkylating agent consisting essentially oi an alkyl bromide at a temperature of from-about- 100 to about 500 C. under a pressure of from sub stantially atmospheric to approximately 200 all-- mospheres in the alkylating catalyst consisting essentially of at zene and said alkyl bromide for production 'joi mono-alkylated benzene.

7. A process for producing a substantial yield of mono-alkylated benzene which comprises conoxide capable under said conditions of molecular proportions of said reactants, temperature and pressure of catalytically promoting condensation reactions between said benzene and said alkyl bromide for production of mono-alkylated benzene.

8. A process for producing a substantial yield of mono-allwlated benzene which comprises contacting from about 1 to about 20 molecular propresence of hydrogen and oi an 9. A process for producinzethyl benzene which molecular proportions of benzene with 1 molecu lar proportion of an alkylating agent consisting essentially! an ethyl halide .at a temperature of from about 100? to about 500 C. under a pressum of from substantiallyv atmospheric.to approximately 200 atmospheresv in the presence of hydrogen and of an alkylatins catalyst consistin essentially oiv at least one metal oxide capable under said conditions of molecular proportions of said reactants, temperature and. pressure of catalytically promoting condensation reactions between said benzene and said ethyl halide for production of ethyl benzene.

10. A process for producing which comprises contacting from about 1 to about 20 molecular proportions of benzene with 1 moiecular proportion of an alkylating agent consist-' in; essentially of a butyl halide at a temperature of from about 100 to about 500 C. under a pressure of from substantially atmospheric to approximately 200 atmospheres in the presence of hydrogen and of an alkyiating catalyst consisting essentially oi at least one metal oxide capable unqder said conditions of molecular proportions of said reactants, temperature and pressure, of catalytically promoting condensation reactions between said benzene and sai duction of a butyl benzene;

11. A process for producins'isopropyl benzene which comprises contacting from about 1 to about 20 molecular proportions of benzene with 1 moa butyl. benzene lecular proportion of an alkylatins a ent consisting essentially of an isopropyl halide at a temperature of from about to about 500 0. under 5, pressure of from substantially atmospheric to approximately 200 atmospheres in the presence of hydrogenand of an alky-lating catalyst consistin; essentially of at least one metal oxide.

12. The process as defined in claim 2 further characterized in that said aromatic hydrocarbon is benzcne.-

13. The process as defined in claim 5 further characterized in that said catalyst contains aluminum oxide in addition'to the zinc oxide.

14. The process as defined in claim 2 further characterized in that said catalyst contains aluminum oxide.

15. The process as defined in claim 4 further characterized in that said catalyst contains aluminum oxide in addition to the zinc oxide. I

16. The process as defined in claim 1 further characterized in that said catalyst contains'aluminum oxide.

1'7. The process as vdefined in claim 2 further characterized in that said alkyl halide is a monochloro-alkane. I

LOUIS SCHMERLING. ARTHUR M. DURINSKI. 

